First off, the ML is a true villain, not misunderstood or trying to exact revenge or something. Contrary to the title, I don't feel there is anything virtuous about him. So the whole cliche romance of him being softened by the FL and that the FL chooses him bc he paid an ounce of attention to her (over other people who came to her rescue and were far less selfless in their decisions) is hard to ship.
He forces an engagement on her by threatening her life, schedules the engagement events without notifying her and generally doesn't show any consideration for the FL aside from showering her with presents. He kills the emperor (who was already a puppet king to the ML's father after being blamed by the people for a disease that spread across the empire), makes the young new emperor (the FL's brother) his personal puppet king, makes the boy sign over his power by threatening the FL, threatens the boy's life/safety repeatedly to make the FL give up stuff, contemplates killing the boy to make his own life easier while the FL begs him not to, almost isolates the poor boy by sending to another palace even after another noble said he'd send assassins waiting to kill the boy (and only cancelled those because of his feelings for the FL, but even then only after she tried to sneak away with the young emperor), still forces the young emperor into an annex in the palace where the boy can't even leave to take a walk outside, and the FL has to ask the ML for PERMISSION to walk around the palace with her brother 40 chapters in
Overall, he has the makings of a typical power hungry noble, but those conflict with the makings of a ML.
Meanwhile, the FL has no personality. I would feel ambivalent towards her if she wasn't the one the plot revolves around. But she is, so half the time I'm just frustrated with her lack of response to anything of importance.
! oh, this character that I wrote to be super dangerous and obsessed with the character I am engaged to has shown up unannounced for tea and I think she's so dangerous that she may have poisoned the tea (oh, but the tea isn't poisoned, so obviously she must not be dangerous AT ALL or would try something else to harm me, the women standing in this character's way) poisoned flowers show up and nearly kill me! (how scary! but why would I look into who sent them), someone found out about my secret power besides the person who's been teaching me to use it! (Let me NOT let my teacher know, even though the person confronting me is from the same place as my teacher! Oh no, now they've kidnapped me), now I've been kidnapped and am held captive in a church (but why would I look for a way to escape besides trying to leave through the front door), my adorable sweet lovely brother keeps getting his life and power threatened and stolen by the ML, and I want to escape with him from the palace (but let's continue to live here, and I also won't look to find anyway to help my brother stay safe and keep his power as emperor. But now that I have to choose whether to help or kill the ML, I'll run away so I don't have to choose. 🤦🏽♀️)
She feels less like a heroine and more someone that things happen to, to allow the ML and other characters to grow.
The only character I like is the young new emperor. He's always trying to find ways to help the FL, and the consideration is rarely returned due to her unexplainable love for the ML and overall inability to take action aside from using her powers. This would have been better as a siblings overcoming adversity together novel as opposed to a romance. FL needs to dump ML on his behind.